get property by index

[rkd77]

In mozjs52 JSClass had method getProperty. Newer versions have not. Could you add an example how to properly access elements by index?
For example getElementsByTagName() returns array. a = document.getElementsByTagName("H1")[5];

[evilpie]

Do you mean something like JS_GetElement that takes an uint32_t index?

[rkd77]

I don't know. getElementsByTagName(...) returns some object. and now I want to code somehow class for this object, so it can be accessed by index. In mozjs52 I had:

static bool
htmlCollection_get_property(JSContext *ctx, JS::HandleObject hobj, JS::HandleId hid, JS::MutableHandleValue hvp)
{
   jsid id = hid.get();
...
   if (JSID_IS_INT(id)) {
                JS::RootedValue r_idval(ctx, idval);
                JS_IdToValue(ctx, id, &r_idval);
                int index = r_idval.toInt32();
                return htmlCollection_item2(ctx, hobj, index, hvp);
        }
...
}

JSClassOps htmlCollection_ops = {
  JS_PropertyStub, nullptr,
  htmlCollection_get_property, JS_StrictPropertyStub,
  ...
};

but AFAIK, in mozjs78 there is no getProperty in JSClassOps.
So question is how to achieve similar result with mozjs78.

[ptomato]

Right, getProperty and setProperty were removed from JSClassOps. You will either have to use lazy property resolution (example https://github.com/mozilla-spidermonkey/spidermonkey-embedding-examples/blob/esr78/examples/resolve.cpp) or pre-define the properties.